Gas Mixed Flow Alarm Function - Oval ALTI mass Series Instructions Manual

L-770HP--E
900
800
700
600
500
400
300
200
100
0
ON
OFF
Low alarm arises
as instant mass
flowrate falls below
low alarm value.
20mA
Analog
output 2
4mA

8.10 Gas Mixed Flow Alarm Function

If gases exist in large quantities in the process fluid, accurate flow measurement will be disturbed.
This feature, if correctly set, detects gases entrapped in the fluid by the following output: [Blinking Red
LED/Fix instantaneous flowrate at 0/Fixed output of pulse and analog output as 0 or upscale/Status
output]
If you do not wish to use this function, set the higher limit density value of slug flow to 0 g/ml and the
lower limit density value of slug flow to 0 g/ml. This function then will remain disabled. The setup
procedure of slug flow function is outlined below.
■Setup procedure
Make sure to set all required individual items.
（）Slug low limit (Lower limit density of slug flow) .
Upon detection of density smaller than this setting, the circuitry interprets and judge as slug flow.
Set a value small enough against the expected density value of the measurement fluid.
（）Slug high limit (Higher limit density of slug flow) .
Upon detection of density larger than this setting, the circuitry interprets and judge as an error.
Set a value large enough against the expected density value of the measurement fluid.

H/L alm active
Low alarm canceled as instant
mass flowrate exceeds [low
alarm + H/L alarm hysteresis].
H/L alm active
High alarm arises High alarm canceled as
as instant mass instant mass flowrate falls
flowrate exceeds below [high alarm + H/L
low alarm value. alarm hysteresis].
High alarm
｝
[900]
Hysteresis
of H/L alarm
[100]
｝
Low alarm
[200]
Time